Cov chaw taws teeb tsis zoo hauv OpenBSD IPv6 pawg

Hauv cov txheej txheem keeb kwm yav dhau los slaacd, uas yog lub luag haujlwm rau IPv6 chaw nyob autoconfiguration (IPv6 Stateless Address Autoconfiguration, RFC 4862) hauv OpenBSD, muaj qhov tsis zoo tau raug txheeb xyuas uas ua rau muaj qhov tsis txaus thaum tau txais kev tshaj tawm tshwj xeeb IPv6 router (RA, Router Advertisement) .

Thaum xub thawj, IPv6 qhov chaw nyob autoconfiguration functionality tau siv nyob rau hauv cov ntsiav tshuaj, tab sis pib nrog OpenBSD 6.2 nws tau tsiv mus rau ib qho kev cais tsis muaj cai slaacd. Cov txheej txheem no yog lub luag haujlwm rau xa RS (Router Solicitation) cov lus thiab parsing RA (Router Advertisement) cov lus teb nrog cov ntaub ntawv hais txog lub router thiab kev sib txuas hauv network.

Thaum Lub Ob Hlis, slaacd tau kho cov kab laum uas ua rau nws poob yog tias 7 servers tau teev tseg hauv RDNSS (Recursive DNS Servers) cov npe. Qhov kev saib xyuas no tau nyiam cov neeg tshawb nrhiav ywj pheej uas tau sim tshuaj xyuas cov cai slaacd rau lwm qhov yuam kev uas tshwm sim thaum txheeb xyuas thaj chaw hauv RA cov lus. Kev tsom xam pom tias muaj lwm qhov teeb meem hauv cov cai, uas tshwm sim nws tus kheej thaum ua tiav DNSSL (DNS Tshawb Nrhiav Cov Npe) teb, uas suav nrog cov npe ntawm cov npe sau npe thiab tus tswv tsev qauv rau DNS.

Txhua lub npe nyob rau hauv daim ntawv teev npe DNSSL yog encoded siv ib tug null delimiter thiab intervening ib-byte tags uas txiav txim qhov loj ntawm cov ntaub ntawv raws li nram no. Qhov tsis zoo yog tshwm sim los ntawm qhov tseeb tias nyob rau hauv daim ntawv teev npe parsing code, ib daim teb uas muaj qhov loj me tau theej rau hauv qhov sib txawv nrog hom kos npe ("len = data[pos]"). Raws li, yog tias tus nqi tau teev nyob rau hauv daim teb nrog qhov tseem ceeb tshaj plaws teeb tsa, tus nqi no yuav raug pom hauv tus neeg teb xov tooj raws li tus lej tsis zoo thiab daim tshev rau qhov loj tshaj plaws ("yog tias (len> 63 || len + pos + 1> datalen) {“) yuav tsis ua haujlwm, uas yuav ua rau hu rau memcpy nrog qhov ntsuas uas nws qhov loj ntawm cov ntaub ntawv theej dhau qhov tsis muaj qhov loj me.

Tau qhov twg los: opennet.ru